The present invention relates to dentistry in general, and more particularly to a dental tool shank which permits a variable longitudinal extension of the shank from a hand piece associated therewith for convenient access to operative areas of the patient's mouth, where preferably an upper head portion of the shank may be severed from the body of the shank to reduce the length of the shank.
In the use of dental hand pieces in the mouth of a patient, it is often found that the jaw-separation of the patient is inadequate to allow the head of the hand piece carrying a suitable attachment such as a drill, burr, anchor and the like to be placed in operative position with respect to the teeth of the patient, especially the posteriors. In the vestibular area of the mouth, it has also been found that the cheek and the tongue do not readily permit access to the normal hand piece provided with conventional tooth attachment extensions.
It is noted, that a prior art adjustable rotatable tool and a holder therefor is disclosed in my U.S. Pat. No. 3,576,076, showing a drill having a straight shank provided with graduated recesses along its length for selectively positioning the drill within the holder. The holder is provided with a spring locking member for releasably holding the drill at the selected position. The head portion of the holder is provided with a flat surface and a circumferential groove for mounting within a dental hand piece.